Method for direct spinning of polyethylene-1,2-diphenoxyethane-p,p{40 -dicarboxylate fibers

ABSTRACT

Commercially useful polyethylene-1,2-diphenoxyethane-p,p&#39;&#39;dicarboxylate fibers are obtained by the direct spinning of a melt of polyethylene-1,2-diphenoxyethane-p,p&#39;&#39;-dicarboxylate with a commercially feasible take-up speed of 1800-3500 m/min by maintaining an intrinsic viscosity and a residual carboxyl group of said polymer within the range of 0.4-1.3 and less than 20 equivalents/106 g., respectively, and when the monofilament denier is as thin as 1.5 - 0.3, the take-up speed can be reduced to a value of 1000-1800 m/min.

United States Patent [191 Kobayashi et al.

[ METHOD FOR DIRECT SPINNING OF POLYETHYLENE-l,2- DIPHENOXYETHANE-P,P DICARBOXYLATE FIBERS [75] Inventors: Hidehiko Kobayashi, Tokyo;

Masatsugu Yoshino,

Saitamaken; Kazuya Neki, Saitamaken, all of Japan [73] Assignee: Asahi Kasei Kogyo Kabushiki Kaisha, Osaka, Japan [22] Filed: Mar. 26, 1969 21 App1.No.: 810,775

[30] Foreign Application Priority Data Apr. 9, 1968 Japan 43-2306] [52] US. Cl 264/176 F; 260/47 C; 264/210 F [51] Int. Cl. D01D 5/08 [58] Field of Search 264/210, 290, 176; 260/47 C, 75 R [56] References Cited UNITED STATES PATENTS 2,604,667 7/1952 Hebeler 264/168 2,604,689 7/1952 Hebeler 264/168 2,957,747 10/1960 Bowling 264/210 F 3,048,467 8/1962 Roberts et al. 264/210 F 3,161,710 12/1964 Turner 264/236 July 15, 1975 3,215,486 11/1965 Hada et al. 264/210 F 3,361,859 1/1968 Cenzato 264/210 F 3,475,381 10/1969 Price et a1... 260/75 3,513,110 5/1970 Noether 264/290 3,624,031 1 1/1971 Kobayashi et al 260/47 C 3,642,697 2/ 1972 Kobayashi et a] 260/47 C 3,654,225 4/1972 Kobayashi et al 260/47 C FOREIGN PATENTS OR APPLICATIONS 131,320 ll/1946 Australia 260/47 C 1,046,069 lO/l966 United Kingdom.... 260/47 C 1,047,978 11/1966 United Kingdom.... 264/290 T 567,106 12/1958 Canada 264/75 Primary ExaminerJay H. W00 Attorney, Agent, or Firm-Fred Philpitt [57] ABSTRACT Commercially useful polyethylene-1,2- diphenoxyethane-p,p-dicarboxylate fibers are obtained by the direct spinning of a melt of polyethylene-l,2-diphenoxyethane-p,p'-dicarboxylate with a commercially feasibletake-up speed of 1800-3500 m/min by maintaining an intrinsic viscosity and a residual carboxyl group of said polymer within the range of 0.4-1.3 and less than 20 equivalents/10 g., respectively, and when the monofilament denier is as thin as 1.5 0.3, the take-up speed can be reduced to a value of 1000-1800 m/min.

5 Claims, N0 Drawings 1 METHOD FOR DIRECT SPINNING OF POLYETHYLENE- l ,2-DIPHENOXYETHANE-P,P DICARBOXYLATE FIBERS 1n the production of fibers from a linear high molecular weight polymer which is spinnable by a meltspinning process, it has been common heretofore to rely on a process which comprises stretching nonstretched fiber filaments having low tenacity, high elongation, low, crystallinity and poor orientation to improve their crystallinity and orientation. Namely, it has required the two steps of (a) spinning and (b) stretching in the production. i

It is not desirable to have two steps in the fiber formation from the standpoint of labor, equipment, apparatus, and production capacity. 7

For the production of useful fibers having high tenacity and low elongation only by the step of spinning, it is necessary to provide crystallinity and orientation sufficient as fibers to the fiber filaments spun during their travel from a spinneret to a take-up point. Attempts to take up extruded fiber filaments at such high velocities, such as more than 5200 yd./min., and 30005200 yd./- min. have been proposed in US. Pat. No. 2,604,667 and 2,604,689, respectively.

However, such high speed taking up as abovementioned, not only is accompanied by mechanical difficulties and danger but also the fiber filaments taken up at such high velocities have relatively large residual elongation and low yield strength. On this account, resultant fiber filaments bring about many difficult points when used practically in subsequent steps of processing such as the problems encountered in the steps of weaving, processings and treatment thereof and the problem of non-uniformity of woven products.

Accordingly, it is an object of the present invention to provide a method for directly spinning polyethylenel,2-diphenoxyethane-p,p'-dicarboxylate fibers which permits one to overcome the above-mentioneddrawbacks of conventional direct spinning methods.

Other objects and advantages will be apparent from the description which hereinafter follows. It has been discovered by the inventors of the present application that fibers having extremely useful properties can be obtained from polyethylenel ,2-diphenoxyethane-p,p'- dicarboxylate which satisfies specified conditions by taking up the filaments at a velocity much lower than that expectable from conventional way of thinking.

Namely the present invention consists in a novel direct spinning method of polyethylene-1,2- diphenoxyethane-p,p-dicarboxylate fibers which comprises taking up the filament yarns spun with a common spinning machine from polyethylene- 1,2- diphenoxyethane-p,p-dicarboxylate which satisfies specified conditions.

The polymers used in the practice of the present invention must be a polyethylene-1,Z-diphenoxyethanep,p-dicarboxylate containing at least 70 mol.% of repetition unit of -m-C-O-CH -CH whose intrinsic viscosity [1 of polymer is more than 0.4 and less than 1.3, (inclusive) and containing less than 20 eq./10 g. (inclusive) of residual carboxyl group in the polymer.

An intrinsic viscosity [1 of the polymer less than 0.4 and more than 1.3, is not preferable because breakage of filaments frequently occurs in such cases.

When the amount of residual carboxyl radical in the polymer is more than 20 eq./l0 g. and the filaments are taken up at such a low speed as above-mentioned, only filaments having low yield strength can be obtained. On the other hand when it is less than 20 eq./ 10 g. superior fibers having a high yield strength can be obtained even when filament yarns are taken up at a relatively low take-up speed. Further the spinnability at the time of actual spinning is exceedingly superior and the fibers having very high stability can be obtained at a spinning temperature ranging from 255 to 320C with a high production efficiency even in case of a high speed take-up, regardless to say, in case of relatively low speed take-up.

The intrinsic viscosities [7 herein referred to, are values as measured in a solvent consisting of a 2:1 mixture by weight of tetrachloroethene and phenol at 35C.

The residual carboxyl radicals herein referred to, are values measured by a method which resorts to titration with a solution of causticsoda and benzyl alcohol by using, as a solvent, benzyl alcohol, and, as an indicator, phenol red. [See H. H. Pohl (Annal. Chem., 26, 1614 (1954)].

The yield strengths herein referred to, are values determined from stress-strain curves in case where samples 20 cm long are stretched at an elongation speed of per minute.

When samples do not show clear yield point, they are determined as an intercepting point of two lines intrapolated from both low elongation side and high elongation side.

The above-mentioned polymer can be produced by subjecting l,2-bis-(paracarbomethoxy .phenoxyethane or its ester-forming derivatives and ethylene glycol to ester-exchange reaction in the presence of a catalyst to form bisglycol of 1,2-bis- (paracarbomethoxy)-phenoxyethane and then subjecting the latter to condensation polymerization in the presence of a polymerization catalyst, at an elevated temperature and under a reduced pressure while eliminating excessive glycol produced in the condensation.

in the production of the above-mentioned polyester ether, it may be possible to add a small amount of one or more comonomers, i.e. one or more of the substances selected from glycols other than ethylene glycol, dicarboxylic acids and hydroxycarboxylic acids. Thus the constitution material suitable to the method of the present invention and consisting essentially of polyethylene-1 ,2-diphenoxyethane-p,-p-dicarboxylate may contain upto 30 mol of another glycol such as diethylene glycol, tetramethylene glycol, hexamethylene glycol or the like. Further, the molecule may contain up to 30 mol of another acid. .Illustrative copolymerizable acids suitable to the present method include hexahydroterephthalic acid, terephthalic acid, isophthalic acid, bibenzoic acid, adipic acid, sebacic acid, azelaic acid, naphthalic acid, 2,5-dimethyl terephthalic acid.

These third component may be added during the polymerization step, or beforethe reaction together with initial starting materials. Alternatively, it is also possible to polymerize it separately and mixed with polyethylene-l ,2-diphenoxyethane-p,p .-dicarboxylate by meltln the practice of the method of the present invention, fibers having a yield strength of more than 1.0 g/d, an initial modulus of elasticity of more than 70 g/d, a breaking strength of morethan 3.0 g/d and a residual elongation of less than 80% can be obtained by taking up the fiber filaments produced by melt-extrusion at a speed of more than 1800 m/min. but a take-up speed greater than 3500 m/min. is not preferable because it brings about frequent breakages of filaments.

According to the method of the present invention which is characterized in taking up filaments at a relatively low speed, it is surprising enough that the lower limit of taking-up can be reduced nearly down to a common spinning speed in the spinning of fine filaments. Namely, in case monofilament denier is in the range of less than 0.5 and greater than 0.2 (inclusive), it is possible to produce fibers having a large tenacity and useful in the practical use even at a take-up speed of 1000 m/min and in case monofilament denier is about 1.0 d, it is possible to produce fibers having a large tenacity and useful in the practical use even at a take-up speed of 1500 m/min.

Application of a common production method of synthetic fibers consisting of two steps of spinning and stretching, to such ultrafine filaments as abovementioned, is difficult because of various problems such as breakage of yarns or monofilaments and development of fluff but application of the direct spinning method according to the present invention has made the production of ultrafine filaments possible with exceedingly high efficiency. However, application in case of less than 0.2 denier is not preferable on account of increase of breakage of monofilaments.

As above-mentioned, the fibers obtained in the method of the present invention have properties superior to those of the filaments obtained by a conventional direct spinning method but it is possible to .provide a production method of practically very useful fibers furnished with even much more superior properties if considerations are given to various conditions such as those regarding the polymer, spinneret, the temperature of atmosphere surroundingthe course of extruded filaments upto a take-up point, method for taking up filaments and proper limitations thereof. Description will be directed firstly to the condition regarding the polymer.

Any known combination of ester-exchange catalyst and polymerization catalyst useful in the production of polymer can be utilized so long as residual carboxyl radical in the polymer becomes less than eq./10 g. (inclusive) by the proper selection of other polymerization conditions such as polymerization time and temperature but when a combination system consisting of a specified ester exchange catalyst and polymerization catalyst is used in the production of polymer, and fibers are produced therefrom by a high speed spinning process, resultant fibers have particularly excellent properties such as greater yield strength, greater breaking strength, lower residual elongation, etc.. As preferable combinations of ester exchange catalyst and polymerization catalyst, combinations of a barium compound invention.

and a .tin compound; a barium compound and an antimony compound; a calcium compound and an antimony compound; are illustrated.

Useful compounds for ester exchange catalyst include elementary metal,.carbonate, oxide, hydroxide, acetate and borate of barium orcalciurn.

Asvantimony compounds useful for polymerization catalyst, salts of antimony with inorganic or organic acid, double salts such as potassium, antimony tartrate salts of antimonic acid, (e.g. ammonium pyroantimonate), oxides, glcoside, catechol complex salts, etc. are illustrated.

As tin compounds, organic tin compoundsexpressed by ageneral formula of R,,,S,,X 'are suitable. [wherein Sn is tin atom, m is an integer of l-4, Vx is a valency of X atom, 4-m/vx is an integer of 0-3, R is an aliphatic group having 1 l8 carbon atoms, acyclic radical having 3-6 rings, or an aromatic group, and X C R. v halogen, -0-, or

, The above-mentioned ester-exchange catalyst is used in an amount'of 0.005 0.5% (inclusive) be weight, preferably 0.0l0.3% (inclusive) by weight relative to the produced polymer. The above-mentioned polymerization catalyst is used in an amount of 0.005-0.5% (inclusive) by weight, preferably 0.0l-0.5% (inclusive) by weight relative to the produced polymer.

The addition of a phosphor compound such as triphenyl phosphite, phosphoric acid, phosphorous acid, as a stabilizer for coloring, and TiO as a delustering agent, is not harmful to the effectiveness of the present When the catalyst system consisting of the abovementioned specified combination is used in the production of polymer, the crystallization velocity of the resultant polymer is particularly fast. Half crystallization time as measured by changing the temperature of polymers melted at 290C for 10 minutes immediately to 220C and maintaining the polymers at this temperature by using aDifferential Scanning Calorimeter made by Perkin Elmer C0,, is within 2 minutes. This fast crystallization velocity is believed to give advantageous infiuence uponstretching, orientation and crystallization at the time of high speed taking-up.

It is really surprising that such a small amount of catalyst system gives advantageous influence upon the properties of fibers and usefulness of themethod of the presentinvention can be highly evaluated.

Description will be directed secondly to the condition regarding spinneret. It is preferable that the hole diameter of spinneret used in the spinning of the present invention is greater than 0.25 mmd) and smaller than 0.9 mmdJ (inclusive). When it is within this range, the stability is extremely good at the time of spinning. When the hole length of spinneret is greater than 1.5 mm and smaller than 10 mm (inclusive), most uniform fibers can be obtained. When it is smaller than 1.5 mm,

Description will be directed thirdly to the condition of the atmosphere. It is preferable to make extruded filament yarns pass through a hot atmosphere maintained at C 180C over the range of distance from the spinneret longer than 30 cm and shorter than 2 m be fore taking-up. It is not preferable to extrude melted material in a cold atmosphere of lower than 10C or to do extrusion in the state that gas or spray of liquid cooled below 10C is being blown to a spinneret because the yield strength of fibers is reduced. It is also a condition which lowers the orientation of molecular chain of filament yarns and affords products inferior in physical properties to make filaments pass in a hot at- I mosphere higher than 180C. It is neither preferable to adopt a heating range shorter than 30 cm, nor a longer range than 2 m. In the control of hot atmosphere, beside the control of cooling speed by way of dried hot wind which has been conventionally used in the spinning of polyester-type fibers, the use of hot wind wetted upto higher than 65% RH makes the controleasier and affords better result.

Description will be directed fourthly to taking-up method. The term take-up herein used is a device which determines the running speed of extruded filament yarns after cooled and solidified. It is not limited only to a device for winding up filament yarns on bobbins which are used together with a common driving mechanism. It also includes the entire apparatus containing a device which runs the filament yarns at a substantially high speed such as an air jet device, etc.

The material which affords friction comprises a pin which does not rotate or a revolving roller. When a revolving material is used, it is necessary to make the peripheral speed of revolving material slower or faster than the speed of filament yarns.

If such a treatment is given to the surface of the friction-affording material that the friction with the filament yarns is increased, greater effectiveness can be attained.

Based upon the above-mentioned factors which make the method of the present invention advantageous, it is possible to obtain more beneficent result by combining two or more of the factors.

The present invention may be more fully understood from the following examples which are offered by way 6 of illustration and not by way of limitation. All parts and per cent are by weight.

EXAMPLE 1 Polyethylenel ,2-diphenoxyethane-p,p dicarboxylate having an intrinsic viscosity of polymer of 0.65 and an amount of residual carboxyl group of polymer of 1 6eq./l0"' g., produced by the polymerization using 0.03 part of manganese acetate as an ester exchange catalyst and 0.01 part of germanium dioxide as a polymerization catalyst, was extruded through a spinneret having a diameter of each hole of 0.35 mmd and a length of 2 mm at a spinning temperature of 290C and subjected to spinning under varied spinning conditions. Results obtained are indicated in Table I.

COMPARATIVE EXAMPLE 1 Polyethylene-1 ,2-diphenoxyethane-p,p'- dicarboxylate having an intrinsic viscosity of 0.61 and a residual carboxyl radical of polymer of 33 eq./ 10 g., produced by the polymerization using 0.03 parts of manganese acetate as an ester exchange catalyst and 0.01 part of germanium dioxide as a polymerization catalyst, was extruded from a spinneret having a diameter of each hole of 0.35 mm and a length of 2 mm at a spinning temperature of 285C. The properties of fibers obtained under various spinning conditions, are shown in the following Table II.

Table II Initial Take-.up Fineness Yield Tenacity Elongation elastic speed (denier) strength at break at break modulus ("L/min.) (g/d) (g/d) (g/d) EXAMPLE 2 To parts of 1,2-bis-(paracarboxymethoxy)- phenoxyethane, 75 parts of ethylene glycol, 0.01 part of calcium acetate as an ester-exchange catalyst were admixed and resultant mixture was heated at 220C for sel, and heated at 280C under a,"reduce"d: pressureof lower than 0.1 mm Hg'while eliminatin g formed ethylene glycol. The intrinsicyiscosity and'the residual carboxyl group of the polymer were 84 and 13 ,eq JIIO g., respectively. Resultant polymer was extruded from a spinneret having a diameter of each hole of 0.45 mm, 10

a length of each hole of 2 mm arid number of holes of 24 at a spinning temperature of 300C at an" extrusion rate of 12 g./min. and resultant fibers were taken up at a speed of 2500 m/min. whereby excellent fibers having a tenacity of 3.6 g/d, elongation of-38%, initial modulus 15 of elasticity of 114 g/d,

and yield strength of 1.3 g/d were obtained. I

EXAMPLE 3 Polyethylene-l ,Z-diphenoxy p,p'dicarboxylate having an intrinsic viscosity of polymer of 0.73 and a residual carboxyl radical of polymer of 14 eq./10 g., produced by the polymerization using manganese acetate as an ester exchange catalyst and ethanegermanium dioxide as 'a.polymerization'catalyst, was

Yield Tenacity iElon g- Young's strength (g/d) ation modulus (g/ I (g/ Fineness of monofilarnent (denier) Take-up speed (m/min.)

Table. 111 -,Cont1n ued Takc up Fineness. :Yield Tenacity Elong- Young's speed monofilament strength (g/d) ation modulus (m/min.) (denier) (g/d) (g/d) 2.1 0.7 2.6 71 76.5 i 2000 0.51 1.8 3.7 46 98.3 i 1.3 1.4 3.2 52 99.9 2.6- 1.2 3.1 58 103.2 2500 7 0.43 1.9 4.0 41 103.1 1.5 -.l.4 3.6 49 106.3 2.4 v 1.3 3.4 54 105.6 3000 0.62 2.1 4.1 36 112.1 "1.6 1.9 3.7 50 109.5 3.4 1.8 8 3.2 53 100.0

. EXAMPLE'4 90 parts'of 1,'2-bis(p carbomethoxyphenoxy)-ethane and parts of ethylene glycol were heated at 220C, for 41161 in the presence of an ester exchange catalys'jt, and formed methanol was eliminated. i

Thereafter, the resultant mixture was heated at 280C, under a reduced pressure below 1 mm Hg, in a polymerizationivessel", in the presence of a polymerization catalyst, 0.03 part of TiO as a delustering'agent and 0.1 'part of 'triphenyl phosphite as a stabilizer, and formed ethylene glycol was eliminated. The intrinsic viscosities of the polymer and the amounts of residual carboxyl group in'th'e polymer producedi n the presence of various ester'exchang'e catalysts and polymerization catalysts are shovvn in the'following Table IV. These polymers were subjected to melt-spinning using a spinneret having a diameter of eachhole of 0.35 mm and a length of 2 mm; and'resultar'it filament yarns were taken at a take up speed of 2400 m/min. Thus, fibers vvhose monofilament denier is. 2 were obtained. The physical propertie's of resultant fibers are shown in the sixth and subsequent columns in the following Table IV. l v

T able.lV

Half crystallization time Amount of residual carboxyl radicals (eq./ 10 g) Intrinsic Catalyst system viscosity and amount. ester exchange catalyst! polymerization catalyst (amount [part]) Spinning. Fineness temperature Elongation x1616 Tenacity Young's strength (g/d) 4 (gm) Modulus (denier) Table IV Cont1nued Catalyst system Intrinsic Amount Half Spinning Fineness Yield Tenacity Elonga- Young's and amount, viscosity of crystaltempera- (denier) strength (gld) tion Modulus ester exchange 1;] residual lization ture (g/d) (g/d) catalyst/ carboxyl time (C) polymerization radicals catalyst (eq./ 1 g) (amount lpartl) Mn acetate] germanium dioxide (0.03 part/ 001 part) 0.79 3'40" 300 2.0 1.4 3.4 57 105.6 Mn acetate/ antimony trioxide (003 part/ 0.03 part) 0.78 11 4'30" 2.0 1.4 3.5 56 107.2

EXAMPLE 5 EXAMPLE 6 The polymer used in Example 1 was melt-extruded from a spinneret having holes of 2 mm length and various diameters; at a spinning temperature of 290C.

Fibers whose monofilament denier was 2 were ob tained at a take-up speed of 3000 m/min. The spinning conditions in this case are shown in the following Table V, in term of number of times of breakages of fibers in case of continuous spinning carried out for 8 hours. The physical properties of fibers obtained in the spinning carried out under the same conditions and by the use of a spinneret having holes of various lengths and diameters, are shown in Table VI, expresssed in term of deviations from the arithmetic mean values in the The polymer used in Example 1 was melt-extruded from a spinneret having a diameter of each hole of 0.35 mmd and a length of 2 mm, at a temperature of 290C. The temperature at the zone apart from the spinneret by 5 to 90 cm was miiintained 'at' a pre-determined point by installing a Heating or cooling tube of l m length immediately" below the spinneret. In another case, a cooling wind of -l 0C was directly blown to the spinneret from a compressor. The physical properties of fibers whose moiifilament denier was 2 and which above-mentioned cases, are shown in' 'Table VII.

measurements of 50 times. Tabl VII Table V Temperature of Yield Tenacity Elongation Young's atmosphere strength modulus Hole diameter Number of (C) (g/ (g (g/d) of spinneret breakage (mmib) of fibers l0C 0.7 3.0 68 99.0 (times) 5 0.9 3.0 63 102.1 10 1.3 3.1 56 105.6 0.15 5.6 40 20 1.7 3.4 51 110.0 0 2 3 80 1.8 3.5 47 113.5 0 25 9 100 2.0 3.6 43 116.3 03 5 160 2.1 3.5 46 115.0 04 4 1 80 L8 3.4 50 113.0 0.5 05 200 0.9 3.2 64 101.0 0 7 0 4 -10 0.6 3.0 69 93.6 (a cooling wind was 12 2.9 blown) Table VI A zone apart from the spinneret bymore than 5 cm was maintained at 140C by installing a heating tube of Spinneret Unevenness Unevenness Unevenness F length Immediately below the spmnertj The diameter length of denier of tenacity of elongati spinning was carried out under the same condition as W (1 demef) (i E (i%) in the above-mentioned case. The physical properties 035 L0 02 1.5 13 of fibers of 2 denier are shown in Table VIII.

1.5 0.1 1.0 7 2.0 0.15 0.6 6 3.0 0.1 0.7 5 Table 111 5.0 0.2 0.3 5 0.5 1.0 0.2 1.5 14

2.0 0.2 3 Length of Yield Tenacity Elongation Young's 3.0 0.15 0.9 6 heating zone strength modulus 5.0 0.2 0.4 5 (cm) (g/d) (g/d) (g/d) 0.7 1.0 0.2 2.3 21

EXAMPLE 7 90 parts of 1,2-bis-p-carbomethoxyphenoxyethane and 7.5 parts of ethylene glycol were heated at 220C, for 4 hours, in the presence of 0.04 part of barium acetate as an ester exchange catalyst, and formed methanol was eliminated. Thereafter, the resultant mixture was heated at 280C, under a reduced pressure below 1 mm Hg, in a polymerization vessel, in the presence of a mixture of 0.03 part of dibutyl tin oxide as a polymerization catalyst and 0.03 part of TiO as a delustering agent and 0.1 part of triphenyl phosphite as a stabilizer, and formed ethylene glycol was eliminated. The polymer thus obtained had an intrinsic viscosity of polymer of 0.73 and a residual carboxyl radical of polymer of 12 eq./l g..

The polymer was melt-extruded from a spinneret having a diameter of each hole of 0.5 mm and a length of 3 mm, at a spinning temperature of 295C, and resultant filaments were taken up at a take-up speed of 3000 m/min., while passing through-a heating tube of l m length installed below the spinneret and maintained at 160C. The fibers thus obtained whose monofilaments denier was 2 denier had a yield strength of 2.4 g/d, a tenacity of 4.2 g/d, an elongation,of 38%, and a Youngs modulus of 118 g/d, and were. excellent in uniformity.

In one Tan (a roll of cloth in Japanese unit, corresponding to about 12 yards) of plain fabric woven using these fibers, there were observed" no dyeing unevenness. I

What is claimed is:

l. A process for the dir'ectspin'ning of commercial useful polyethylene-1 ,2-diphenoxyethane-p,pdicarboxylate fiber without any subsequent stretching operation which comprises extruding a melt of a polymer containing substantially 100-. mol of repetition units of the formula: a

- said polymer having an intrinsic viscosity of between about 0.4 and 1.3, and containing less than about 20.0 eq./l0 g. of residual carboxyl group in the polymer, and taking up the resultant extruded fibers at a velocity ranging from about 1800 to 3500 m/min.

3. A process according to claim 1 wherein the extruded polyethylene-1,2-diphenoxyethane-p,pdicarboxylate is taken up after travelling through a zone maintained at l0-180C and which extends from the spinneret for at least 30 cm.

4. A process according to claim 1 wherein the fibers so produced have a yield strength of at least 1.0 g/d., an initial modulus of elasticity of at least g/d., a breaking strength of at least 3.0 g/d., and a residual elongation of less than 5. The process according to claim 1 wherein said is produced by subjecting l ,2-,bis- (paracarbomethoxy)-phenoxyethane or its ester forming derivatives and ethylene glycol to ester-exchange reaction in the presence of a catalyst to form bisglycol of l,2-bis-(paracarbomethoxy)-phenoxyethane and then subjecting the latter to condensation polymerization in the presence of a polymerization catalyst at an elevated temperature and under a reduced pressure while eliminating excessive glycol produced in the condensation. 

1. A PROCESS FOR THE DIRECT SPINNING OF COMMERCIAL USEFUL POLYETHYLENE-1,2-DIPHENOXETHANE-P,P''-DICARBOXYLATE FOBER WITHOUT ANY SUBSEQUENT STRETCHING OPERATION WHICH COMPRISES EXTRUDING A MELT OF A POLYMER CONTAINING SUBSTANTIALLY 100 MOL % OF REPETITION UNITS OF THE FORMULA:
 2. A process according to claim 1 wherein the melt of polyethylene-1,2-diphenoxyethane-p,p''-dicarboxylate is extruded through a spinneret having hole diameters within the range of 0.25 mm to 0.9 mm and a hole length within the range of 1.5 mm to 10 mm.
 3. A process according to claim 1 wherein the extruded polyethylene-1,2-diphenoxyethane-p,p''-dicarboxylate is taken up after travelling through a zone maintained at 10*-180*C and which extends from the spinneret for at least 30 cm.
 4. A process according to claim 1 wherein the fibers so produced have a yield strength of at least 1.0 g/d., an initial modulus of elasticity of at least 70 g/d., a breaking strength of at least 3.0 g/d., and a residual elongation of less than 80%.
 5. The process according to claim 1 wherein said polymer is produced by subjecting 1,2-bis-(paracarbomethoxy)-phenoxyethane or its ester forming derivatives and ethylene glycol to ester-exchange reaction in the presence of a catalyst to form bisglycol of 1,2-bis-(paracarbomethoxy)-phenoxyethane and then subjecting the latter to condensation polymerization in the presence of a polymerization catalyst at an elevated temperature and under a reduced pressure while eliminating excessive glycol produced in the condensation. 